1. Field of the Invention
This invention relates generally to power trains for roller mills and more particularly to transmissions for rotating opposed rollers in opposite directions at the same speed.
2. Related History
Roller mills for shaping ingots, billets and other stock employed rolling compressive forces for reducing thickness and elongating. The stock material or work piece to be rolled was fed between opposed rollers which were driven in opposite directions and which exerted compressive forces.
In some rolling mill drives, separate electric motors were provided for each of the opposed rollers with the drives configured for rotating the rollers at the same speed but in opposite directions. Some of these drives were inherently unstable, however, and utilized the torque of one motor to balance the other motor in order to synchronize driving speeds. As a result, the two rollers could not be driven constantly at the same speed and with the same torque. Further, such system was not capable of being mounted to a foundation support but rather straddled its inputs and outputs.
In addition, use of these drive systems also resulted in a considerable wear on rotating tires of the roller mill, the replacement of which was quite complicated and time consuming.